What are the best vitamins for cancer patients?

Walk down the vitamins and supplements aisle of a pharmacy or grocery store, and you’ll see a mind-boggling array of options. It can be hard to know which one is best. And if you’re a cancer patient looking for the right dietary supplement, there are even more issues to take into account. How do you know what’s the best – and safest – choice?

Whether you are a cancer patient or survivor, these tips can help you avoid unforeseen side-effects:

Tell your doctor which vitamins you are taking. Studies have shown that some supplements can decrease the effectiveness of cancer treatment. St. John’s Wort, sometimes used for depression, has been shown to lower the effects of chemotherapy by more than half, while vitamin E, vitamin C, selenium, beta carotene, and other anti-oxidants might have similar effects on radiation and chemotherapy. Do you have a question about a particular vitamin? Ask our nutritionist, or check out our questions and answers section.

Read the package carefully. Vitamins and supplements bearing the label “USP” (United States Pharmacopoeia) or “NSF” (National Science Foundation) have been vetted by independent, quality control groups recognized by the U.S. government and are generally safer than those without the label.

“An apple a day” is still the best advice. Eating a balanced diet is still the best and safest way to ensure that your nutritional needs are met. Recently, a number of studies on supplements have been stopped because of concerning side effects. For example, a small preliminary study found that while selenium reduced the risk of ovarian cancer in women who eat foods rich in this anti-oxidant mineral, women who took selenium supplements, and other anti-oxidant vitamins, actually increased their risk of ovarian cancer.

Dietary supplements can be helpful in some cases. Vitamin D is well known for helping the body control calcium and phosphate levels and maintain healthy bones. Because food isn’t a great source of vitamin D (you’d need about 10 glasses of fortified milk to get 1,000 IUs) and too much sun exposure can damage skin, we recommend taking vitamin D supplements. Learn more about vitamin D.

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